Tim Geithner, US Treasury secretary, stiffened his call for derivatives reform on Sunday as lawmakers and officials used allegations that Goldman Sachs committed fraud in marketing complicated financial instruments to push for more transparency....Separately, in a letter to Jean-Claude-Trichet, president of the European Central Bank, Mr Geithner called for co-operation between the US and Europe in deciding which contracts should be forced through central clearing houses and on to electronic exchanges.

The letter, seen by the Financial Times, was sent on Friday and describes a regulatory reform tougher than some Democratic and Republican proposals: "All standard derivative contracts must be traded transparently" on exchanges or other platforms, Mr Geithner wrote, "lowering costs for users of derivatives, such as industrial or agriculture companies".